At 03:13 PM 11/24/01 -0500, Josh Koffman wrote:
>Or how about a 250K pot? Would it really make a difference seeing as I'm
>measuring the relationship between vref and the the analog input?

There's no difference, provided that the chip's input impedance is
infinite, and there's no interfering EMI.
Otherwise, you can calculate the effect of non-infinite input impedance.
EMI is harder to predict, but generally, keeping your source impedance low
keeps this from becoming much of a problem.

Got a need to read Bar codes? http://www.barcodechip.com
Bi-directional read of UPC-A, UPC-E, EAN-8, EAN-13, JAN, and Bookland, with
two or five digit supplemental codes, in an 8 pin chip, with NO external parts.